1. Field of the Invention
The present invention relates to a display device having an image pickup function which can display an image and take an image of an object at the same time. More particularly, the invention relates to a display device having an image pickup function which can take an image of a user as an object and display an image at the same time. In addition, the invention relates to a two-way communication system which can take an image of a user as an object while displaying an image of the others.
2. Description of the Related Art
In recent years, with the advance of telecommunication networks, what is called a two-way communication system such as a videophone system and a video conference has been developed, in which two parties can communicate while viewing an image of each other.
According to the two-way communication system, it is possible to take an image of a user (object) and to display an image of the other party at the same time.
For example, an image pickup and displaying device (shooting device) having a special screen which turns to be transparent or opaque according to an incident angle of light, and an image pickup device and a projector display device each disposed on the back of the screen is disclosed (see Patent Document 1 for example). According to such an image pickup and displaying device, two parties can catch each other's eyes when their images are projected by the projector display device which is disposed in the opaque direction of the screen.
However, according to the Patent Document 1, it requires a special screen as well as an image pickup device and a projector display device, leading to a large and heavyweight device. Therefore, such a device cannot be applied to a portable electronic device.
Meanwhile, a two-way communication system in which two parties can communicate while catching each other's eyes is also disclosed (see Patent Document 2 for example). The two-way communication system includes a display panel having a monitor screen for displaying an image of the other party, a position specifier for specifying the position of a user with respect to the monitor screen, an image pickup unit for imaging of the user, and a support mechanism for setting the image pickup unit between the user and the monitor screen. In particular, the image pickup unit is disposed within the area which corresponds to the position specified by the position specifier and is determined by the parallactic angle in which eyes of two parties can be judged to meet each other, which means the image pickup unit is disposed in the specified position which obstructs a part of the monitor image of the other party.
However, the two-way communication system according to the Patent Document 2 has a problem in that a camera as an image pickup portion is disposed in a projected manner over an entire monitor screen (display screen), which interrupts user's view since the camera partially obstructs the monitor image and thus shades a part of the image.
In addition, a display device having an image pickup function which can display an image and take an image of an object at the same time while securing an eye focus of the user who is viewing the displayed image is disclosed as well (see Patent Document 3 for example). The display device includes a display panel having a display screen, a pinhole portion formed on the display screen, and an image pickup unit which uses the pinhole portion as a light path. According to the structure, it is possible to display an image on the display panel while imaging an image of a user as an object.
However, according to the display device having the image pickup function of the Patent Document 3, a part of a display screen is broken by forming a pinhole thereon even when it has a small diameter, thus obstructs a display with high definition and high quality. In addition, since there is a limitation on the downsizing of the pinhole diameter, the defect in a pixel due to the pinhole becomes relatively large when the display screen is small such as a portable phone. Therefore, it is impossible to completely remove the sense of discomfort of the user
[Patent Document 1]
Japanese Patent Laid-Open No. Hei 6-30406 (Page 2, FIG. 2)
[Patent Document 2]
Japanese Patent Laid-Open No. Hei 9-130768 (Page 10-11, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 2001-231019 (Page 7 to 8, FIG. 5)